According to an embodiment, a database device includes a volatile first storing unit, a non-volatile second storing unit, an access processing unit configured to execute an operation corresponding to an access request for each of a plurality of blocks obtained by dividing data pieces, a backup processing unit configured to write data of each of the plurality of blocks at a backup time to the second storing unit, and a block management unit. The block management unit writes, under certain conditions, data of any block stored in the first storing unit to the second storing unit, and reads data of a block targeted by an access request from the second storing unit to the first storing unit. The backup processing unit writes data of a block that is not yet written to the second storing unit among the plurality of blocks.